The present invention relates to machines for crimping electrical contacts onto wires. Crimping machines are commonly used when a large number of contacts and wires must be crimped, for example, when manufacturing an aircraft wiring harness.
FIG. 1 shows an example of a prior art crimping machine 1, the Porta-Tac manufactured by Tri-Star Electronics, Inc., of Venice, Calif. In operation, the crimping machine automatically obtains a contact (not shown) from a magazine 3 and positions the contact adjacent to an opening 5. The magazine 3 contains a number of electrical contacts of a single type and size. The magazine 3 is removable, allowing the size and/or type of contact to be changed by changing the magazine. An operator (not shown) inserts a stripped end 7 of a wire 9 through the opening 5 and into the contact. When the stripped end 7 is properly positioned, the crimping machine 1 automatically crimps the contact onto the stripped end 7.
A contact of a given size may be satisfactorily crimped to a wire which is as much as two sizes smaller than the contact. For example, an 18 gauge contact may be used for an 18, 20, or 22 gauge wire. However, the crimping depth varies for the various combinations of contact and wire sizes. Thus, the machine 1 has an adjustment knob 11 which allows the operator (not shown) to set the appropriate crimping depth. In this particular machine, there are six settings. To minimize changing the magazine 3 and the adjusting knob 11, the operator will generally group the wires to be crimped by size.
Several crimping errors are possible when using the type of prior art machine described. An improper crimping depth setting will result in a defective crimp. If the crimping depth is too great, the contact may be crushed. If the crimping depth is not sufficient, a loose crimp will occur. In addition, it is possible to insert an unstripped wire into a contact. Each of the mentioned defects can be hazardous, expensive to correct, and, if not detected, cause major problems in use.